Lonergan G J, Martínez-León M I, Agrons G A, Montemarano H, Suarez E S
Department of Radiologic Pathology, Armed Forces Institute of Pathology, Washington, DC 20306-6000, USA.
Radiographics. 1998 Jul-Aug;18(4):947-68. doi: 10.1148/radiographics.18.4.9672980.
The fetal kidney is formed by the development of nephrons from fetal metanephric blastema surrounding the ureteric bud. The fetal renal tissue matures into normal renal parenchyma during gestation, but, occasionally, fetal tissue persists into infancy as microscopic foci called nephrogenic rests. Nephrogenic rests are found in approximately 1% of infant kidneys at autopsy. Nephrogenic rests are associated with an increased risk of Wilms tumor, and it is theorized that nephrogenic rests undergo neoplastic change into Wilms tumor. Fortunately, this transformation occurs in less than 1% of young children with nephrogenic rests. Nephrogenic rests are associated with many syndromes, including Beckwith-Wiedemann syndrome, hemihypertrophy, and sporadic aniridia. Children with identifiable syndromes, once diagnosed, should be screened for the development of Wilms tumor. Nephrogenic rests are associated with other lesions such as multilocular cystic nephroma and multicystic dysplasia, usually without malignant complications.
胎儿肾脏由围绕输尿管芽的胎儿后肾胚芽发育形成肾单位而构成。胎儿肾组织在妊娠期成熟为正常肾实质，但偶尔胎儿组织会以称为肾源性残留的微小病灶形式持续存在至婴儿期。尸检时，约1%的婴儿肾脏中可发现肾源性残留。肾源性残留与肾母细胞瘤风险增加相关，据推测肾源性残留会发生肿瘤性转变为肾母细胞瘤。幸运的是，这种转变发生在不到1%有肾源性残留的幼儿中。肾源性残留与许多综合征相关，包括贝克威思-维德曼综合征、半侧肥大和散发性无虹膜。一旦确诊患有可识别综合征的儿童，应筛查肾母细胞瘤的发生情况。肾源性残留与其他病变如多房性囊性肾瘤和多囊性发育不良相关，通常无恶性并发症。
